C/2025 K1 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Today	30 Jul 2025	12.9	1.598 AU	0.701 AU	19h59m	+23°55'	136.5°	25.9°	166°
Perihelion	8 Oct 2025	7.0	0.334 AU	1.292 AU	12h35m	-12°27'	8.1°	25.0°	217°
Nearest approach	24 Nov 2025	10.3	1.193 AU	0.401 AU	09h34m	+63°56'	111.3°	50.4°	274°

The interactive orbit chart above shows the comet's path through the solar system and its position at the given date. Green and blue lines are shown perpendicular to the ecliptic plane: Green if the path is above the ecliptic plane, blue if it is below. (Left-click and drag to rotate the view; Right-click and drag to move the view; Use scroll wheel to zoom in our out.)

The orbital elements of C/2025 K1 (ATLAS) are:

            e (Eccentricity)                : 1.0002540
            q (Perihelion distance)         : 0.3341790
            i (Inclination)                 : 147.86500
            Ω (Longitude of ascending node) : 97.55630
            ω (Argument of perihelion)      : 271.02710
            L (Longitude of perihelion)     : 186.34343
            B (Latitude of perihelion)      : -32.12922
            T (Time of perihelion passage)  : 2460956.94160

            Epoch                           : 2025 Jul 29
            Reference                       : MPC185661

            Classification(s):              : Nearly isotropic; New (a > 10000 AU)
        

The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations respectively from COBS or the MPC. The gray curve is based on the absolute magnitude and slope parameter as calculated from the original MPEC, or the latest values provided by the MPC (12.20 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 11.48 + 5 log[∆] + 10.65 log[r]).

The all-sky chart below shows the path of the comet over the same period as the light curve. The comet's current position is marked yellow.

The following chart shows the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.
A more printer-friendly version of the same chart can be found further down this page as well.

The following chart shows the current location of the comet in a smaller, upside-down telescopic field of view.

A printable version of the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.

Ephemerides:

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-07-30 00:00 UT   20 04 26.4   +24 02 47     0.712    1.609  136.7   25.7   169   12.9 
2025-07-30 01:00 UT   20 04 04.9   +24 02 19     0.711    1.608  136.7   25.7   169   12.9 
2025-07-30 02:00 UT   20 03 43.3   +24 01 50     0.710    1.607  136.6   25.7   169   12.9 
2025-07-30 03:00 UT   20 03 21.7   +24 01 21     0.710    1.607  136.6   25.7   168   12.9 
2025-07-30 04:00 UT   20 03 00.1   +24 00 51     0.709    1.606  136.6   25.7   168   12.9 
2025-07-30 05:00 UT   20 02 38.4   +24 00 21     0.708    1.605  136.6   25.7   168   12.9 
2025-07-30 06:00 UT   20 02 16.7   +23 59 51     0.707    1.605  136.6   25.8   168   12.9 
2025-07-30 07:00 UT   20 01 54.9   +23 59 20     0.707    1.604  136.6   25.8   168   12.9 
2025-07-30 08:00 UT   20 01 33.2   +23 58 50     0.706    1.603  136.6   25.8   167   12.9 
2025-07-30 09:00 UT   20 01 11.3   +23 58 18     0.705    1.602  136.6   25.8   167   12.9 
2025-07-30 10:00 UT   20 00 49.4   +23 57 47     0.705    1.602  136.6   25.8   167   12.9 
2025-07-30 11:00 UT   20 00 27.5   +23 57 15     0.704    1.601  136.6   25.8   167   12.9 
2025-07-30 12:00 UT   20 00 05.5   +23 56 43     0.703    1.600  136.6   25.9   167   12.9 
2025-07-30 13:00 UT   19 59 43.5   +23 56 10     0.702    1.600  136.6   25.9   166   12.9 
2025-07-30 14:00 UT   19 59 21.5   +23 55 37     0.702    1.599  136.6   25.9   166   12.9 
2025-07-30 14:48 UT   19 59 03.8   +23 55 11     0.701    1.598  136.5   25.9   166   12.9 
2025-07-30 15:00 UT   19 58 59.4   +23 55 04     0.701    1.598  136.5   25.9   166   12.9 
2025-07-30 16:00 UT   19 58 37.3   +23 54 31     0.700    1.598  136.5   25.9   166   12.9 
2025-07-30 17:00 UT   19 58 15.1   +23 53 57     0.699    1.597  136.5   25.9   166   12.9 
2025-07-30 18:00 UT   19 57 52.9   +23 53 23     0.699    1.596  136.5   26.0   166   12.9 
2025-07-30 19:00 UT   19 57 30.6   +23 52 48     0.698    1.595  136.5   26.0   165   12.9 
2025-07-30 20:00 UT   19 57 08.4   +23 52 13     0.697    1.595  136.5   26.0   165   12.9 
2025-07-30 21:00 UT   19 56 46.0   +23 51 38     0.697    1.594  136.5   26.0   165   12.9 
2025-07-30 22:00 UT   19 56 23.6   +23 51 02     0.696    1.593  136.5   26.0   165   12.9 
2025-07-30 23:00 UT   19 56 01.2   +23 50 26     0.695    1.593  136.4   26.1   165   12.8 
2025-07-31 00:00 UT   19 55 38.8   +23 49 50     0.694    1.592  136.4   26.1   164   12.8 

    Terminology:
            
    delta:  distance between comet and earth in AU
    radius: distance between comet and sun in AU
    magn:   magnitude (brightness) estimate    
    ra:     right ascension in hours (24h = 360deg)
    dec:    declination in degrees
    elong:  elongation in degrees (angle sun-earth-comet)    
    phase:  phase angle in degrees (angle sun-comet-earth)        
    AU:     Astronomical Unit (mean distance between earth and sun: 149597870.7 km      
    

Orbital elements usually provided by the MPC (Minor Planet Center).
Observations contributed by observers worldwide, via COBS (Comet Observation Database) or the MPC (Minor Planet Center)
Calculations by a modified version of AAPlus, a C# implementation of the AA+ project by PJ Naughter from the algorithms presented in the book "Astronomical Algorithms" by Jean Meeus.
NGC2000 dso catalog and star labels from VizieR as provided by the Strasbourg astronomical Data Center.
Tycho2 catalog from the ESO archive.